Grease a large (9X13-inch) baking pan with butter (or use cooking spray). Arrange the slices in the pan to fit, overlapping slightly if necessary.
Whisk together the eggs, half and half, milk, vanilla, and cinnamon until combined and pour the mixture over the bread slices.
Make the Gooey Butter Topping
Combine the butter, sugar, salt, and corn syrup in the bowl of a mixer with a paddle attachment. Beat on medium speed until light and fluffy, about 3 minutes. Scrape down the bowl.
On medium low speed add 1 egg and mix until combined. Then mix in the other egg and the vanilla extract.
Add the milk and cake flour and mix on low speed to combine. Scrape down the bowl and give it a final stir.
Dollop the butter topping over the bread and smooth out. Cover with plastic wrap and refrigerate overnight.
Final Preparation
Preheat oven to 350 degrees F.
Bake for 40-50 minutes until the bread has puffed slightly and the gooey butter topping has started to brown around the edges and is a light golden brown. If the edges are browning but the center needs more time, cover the outer edge with aluminum foil and continue baking.
Dust lightly with powdered sugar, and serve.
Notes
It is especially good with something more savory on the side to balance the sweetness; we love bacon and a tart blackberry syrup that was a great addition.Simply mash up some blackberries and combine them with maple syrup in a medium size pan. Heat till simmering and let bubble for five minutes or until the blackberries have softened and released their juices. Drain through a sieve to remove the blackberry seeds before serving.